To grind or re-shim ?

[gsx600racer]

I have a set of Malossi gears 16/32 I am going to install in this build------> 
49ccscoot.proboards.com/thread/15359/2005-kymco-zx50-build-2

The stock gear is .392" wide,


then new gear is .416" wide,


the difference being the new gear is .021" thicker. (yeah I only went 3 places with the math)

So as the title states, should I grind(surface grinder) the gear to the stock gear width or try re-shimming?

I think trying to find a shim that's going to work(.017" thick) is going to be a pain(matching OD and ID + thickness). The current shim is .038" thick 

Thanks

[oldgeek]

Is it the blue washer you are looking to replace or the other side with the metal shim?


Edit: I guess the blue shim would be the one because it is right next to the gear in question. The metal shim is between the smaller gear and the case half.

How about grinding the side that gets pressed next to the small gear. That would keep the side that the blue shim is on untouched.

I know I read somewhere on the Kymco forum that someone tried the malossi gear swap and had trouble/ruined a gearbox for some reason. I believe the blue washer was the suspected reason.

[gsx600racer]

Oldgeek, you are correct. The shim I measured was the steel one. My thought was if I installed the new/thicker gear, it would shift everything towards the steel shim. I am going to see if I can get the gear surface ground to the same thickness as the stock gear. Then the intermediate shaft assemble will be dimensionally the same as stock.




Did you mean this topic ?

www.kymcoforum.com/index.php?topic=3373.msg59813#msg59813

[190mech]

Mcmaster Carr has a good shim selection;
www.mcmaster.com/#standard-shims/=11ryao8

[oldgeek]

I think you have a good plan.

One thing I have been wondering about is the gear mesh angle. The stock gears mesh at an angle, and the direction of the angle should create a bit of thrust to one side or the other correct? I have been sitting here looking at my destroyed ZX primaries and I think the thrust of the stock gears would be in the direction of the blue washer. The malossi gears appear to be straight mesh in your pictures, I wonder if that causes an issue somehow? (Thanks for the pictures!) I know that it is common for aftermarket gears to be straight mesh, but I was wondering if it was causing a problem in this application?

Also I dont think the thread you linked to is the one I was talking about. I believe there is another thread somewhere that discusses the thread you linked to and possible causes.

I think your idea about the Polini Corsa having enough torque for the malossi gears could work out. Do you have a pipe selected for this build yet? I am interested to see how this all works out for you.

[gsx600racer]

Mar 31, 2016 5:37:26 GMT -5 oldgeek said:

I think you have a good plan.

One thing I have been wondering about is the gear mesh angle. The stock gears mesh at an angle, and the direction of the angle should create a bit of thrust to one side or the other correct? I have been sitting here looking at my destroyed ZX primaries and I think the thrust of the stock gears would be in the direction of the blue washer. The malossi gears appear to be straight mesh in your pictures, I wonder if that causes an issue somehow? (Thanks for the pictures!) I know that it is common for aftermarket gears to be straight mesh, but I was wondering if it was causing a problem in this application?

Also I dont think the thread you linked to is the one I was talking about. I believe there is another thread somewhere that discusses the thread you linked to and possible causes.

I think your idea about the Polini Corsa having enough torque for the malossi gears could work out. Do you have a pipe selected for this build yet? I am interested to see how this all works out for you.

Oldgeek, 

I just gave the gear to someone to grind down to day. 

As for the thrust, I would have to sit and look at mine. My gut tells me that gear angle(design) and the force applied you would want it push the gear/s towards the steel shim(not the plastic). I have that shim in front of me and it does not show any wear if that was the case. Then again we are talking about a scooter with very little miles on it. I will check it out later this evening.

As for the thread, if you went a couple pages back, it showed the plastic washer mangled up. Anyways I know what you are talking about. I have a few concerns with this gear swap myself. I am not one just to slap it all together and run with it. I still need to measure up the input shaft too, the gear on that is wider also. All I care about is as long the dimensions add up to the stock shaft, then we are a "GO" to reassemble.

I put a post out on hondaspree in regards to the cylinder fitment issue I am having, seeing that the person I bought the kit from hangs out there (SSS). I'v got a lot of views but no responses yet. Just figured a lot of guys there run that kit in stock and ported flavors on that site, I would get a lot of feed back. I might double post it here here too. I just want to do it right the first time.

I plan on swapping my Tecnigas Next-R chrome from (Kymco 1) and using it on this build. I know the Polini kit screams with a much better pipe(YASUNI C16 or SCORPION PIPE ), but the budget says that's going to have to wait. 

I will be keeping all that are interested up to date with my progress(good or bad). Will be updating my build thread shortly. Plus I want to start another one for Kymco 1.

[oldgeek]

Since treatland is currently having a 16% off sale, I ordered a set of the Malossi gears today. So yeah, I will be watching your progress with much interest!

[gsx600racer]

Mar 31, 2016 20:26:55 GMT -5 oldgeek said:

Since treatland is currently having a 16% off sale, I ordered a set of the Malossi gears today. So yeah, I will be watching your progress with much interest!

Cool, I hope what I have been learning and sharing will help you and other others here. I also appreciate your comments and feedback/help as well. 

[gsx600racer]

Well I got my gear back from grinding today as well as the new bearing.(so I didn't have to press the old one off)




The gear was .003" bigger than I wanted, but it will be fine.(don't sweat the small stuff)



I also re-chamfered all the teeth.



Installed the new bearing on the new input shaft. Was so neat, froze shaft, heated bearing and let gravity do the rest.



EDIT: I forgot to add. I measured the old primary shaft/bearing assemble, it measured 1.797" the new shaft was 1.800" (that .003" is going to haunt me) In the picture above I measured from the outside of the gear(left) to the outside of the bearing(right) Which is basically the space between the two case halves.

All that's left is pressing the new gear on the counter shaft and reassemble the transmission and this chapter is done. Oh ya, and add oil.

[oldgeek]

Apr 1, 2016 22:13:30 GMT -5 gsx600racer said:

Well I got my gear back from grinding today as well as the new bearing.(so I didn't have to press the old one off)




The gear was .003" bigger than I wanted, but it will be fine.(don't sweat the small stuff)



I also rechamfered all the teeth.



Installed the new bearing on the new input shaft. Was so neat, froze shaft, heated bearing and let gravity do the rest.



All that's left is pressing the new gear on the counter shaft and reassemble the transmission and this chapter is done. Oh ya, and add oil.

Ok where did you get the bushing from under the gear in your picture!LoL! I need about 6 of them!

Also, are you going to be able to install the primary shaft bearing assembly in the case by pressing only on the outer race of the bearing? I always try to avoid pushing the inner race of a bearing to install it, because it supposedly dings the bearings? I guess the hot/cold method will get it installed in the case with no pressure on the bearings either, nevermind LoL! Very nice grind BTW!

[gsx600racer]

I got the bushing here,

www.partsforscooters.com/164-157_Gy6_Crank_Bushing?ext=F

Same as the bearing.

www.partsforscooters.com/105-58__6203-P6__Radial__Bearing?ext=F

They are having a sale on Dr Pulley stuff, I picked up a couple sets of sliders too.

I am going to freeze the primary shaft and heat the case and install. Ya I know, some of the tranny guts are going to be in the case and the rest in the tranny case cover. It will be a joy to put together(getting everything to line up) but I wont have to us a hammer to assemble.

Thanks for the props, its getting there. Wait till you see my intake opening updates. The case got even lighter. LOL

[gsx600racer]

Well I had a chance to get out after the snow subsided. I took the gears I needed to get pressed together to a friends shop. I had chilled the intermediate shaft and heated the gear. With the gear coated with a bit of oil it went together nicely.



Then I assembled the transmission to see how everything fit.



The new gears seem to align nicely.


Then I greased any seal lips and coated all moving parts with gear oil and installed the "plastic" washer. The cover went on easier than expected. I torqued all the bolts and added oil. I also reinstalled the brake shoes too.




Well that concludes the transmission build of 2005 Kymco ZX50 build(Kymco 2)